Stay-bolt structure for boilers.



J. R. FLANNERY, B. E. D. STAFFORD & E. I. DODDS.

STAY BOLT STRUCTURE FOR BOILERS.

APPLICATION FILED FEB. 29, |916.

Patented Ovt. 31, 1916.

INVENTUM r5.5 @www e. j, v6 ma .L7/,W flfformy '-f opened to the passage and discharge ofv JOHN ROGERS FLANNERY,

BENJAMIN'. E. D.

STAFFORD, AND ETHAN I. nomas, oF

"PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO FLANNERY BOLT COMPANY, OF

' PITTSBURGH, PENNSYLVANIA.

' STAY-BOLT STRUCTURE FOR BOILERS.

To all whom it may ooncem.'

Be it-known that we, JOHN lROGERS FLAN- NERY, BENJAMIN E. D. STAFFORD, and ETH-AN I.: DoDDs, citizens of the United States, and residents of Pittsburgh, in the`rl county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolt Structures for Boilers; and we'do hereby'declare the following to be a full, clear, andexact description of the invention, such as will enable others skilled in the art tov whichA it appertains to make and use the same.

' This invention relates to improvements in stay bolt structures for boilers,-the object ofthe invention being to provide simple and eiiicient means whereby a tell-tale opening in the stay boltmay be normally sealed against the entrance` of dust, etc., and whereby, when the bolt becomes fractured, cracked or broken, the said tell-tale hole will be water or steam to denote the damaged condition of the bolt.

With this and other objects in view, the invention consists in certain novel features of construction and combinations of parts as hereinafter set forth and'pointed out in the claims. f

The accompanying drawing, is a sectional view of a stav bolt structure showing an embodiment of our invention.

1- represents the outer sheet of a boiler having a threaded opening for the accommodation of an externally threaded sleeve 2. The sleeve 2 projects beyond the outer boiler sheet 1 and receives a cap 3 which is preferably curved to conform to the curvature of the head 4 of the stay bolt 5, said head having a rocking bearing within the sleeve 2. The cap 3 is made with a. central opening 6 which is normally closed by a thin disk 7 of soft or frang'ble metal or other material which may be easily destroyed or broken by impact. The disk 7 is normally held in place by the engagement of a tubular plug 8 screwed into an annular boss 9 on the cap. The stay bolt is made with an axial telltale hole or opening 10, a portion 11 of which within the head of the bolt preferably beingsomewhat enlarged and open at the outer end of the bolt head in line with the disk or closure 7 in the central opening of the cap.

Speccation of Letters Patent.

.Patented'oeti 31,1916.

Eppliatio'n inea Fbmjary 29, 191e. serial No. 81,262.

The larger portion 11 of the' bore of the 'tell-tale hole or openmglserves to receivea plunger or projectile 12 having a -pointed end portion 13, and within the smaller p0rtlon of Y the bore of the.Ttell-talejhole, a materlal or compound 14 isplacedfwhi'ch, lwhen subjected tothe action vof `moisture,f will cause the setting up of reactions which will result in the generation of gas having suiiicient pressure to expel the plunger or jprojectile 12.

As an example of the material which might be -employed in the tell-talel hole, metallic sodium may be mentioned.

r1 he wall of the larger portion 11 of the tell-tale hole is made with an annular groove 15 which receives the beaded or enlarged edge 1G vof a Cone 17 made of Asoft or readily penetrable metal disposed to inclose the pointed end portion 13 of the plun- 4 ger or projectile and normally preventthe entrance of moisture to the material behind the projectile. vThe space within the .portion 11 0f the tell-tale bore may* contain stiff grease or other easily penetrable packing 18 which will serve to augment the cone 13 in normally excluding moisture.

Under normal conditions, the material and devices within the tell-tale opening will serve to exclude dust, etc., which might clog said tell-tale hole, but if the bolt should become fractured, as indicated at 19, water will enter the hole or bore 10 and come into contact with the material contained .in said hole or bore. The result will be the setting u p of reactions which will tion of gaseous pressure sufficient to expel the projectile and cause its pointedy end to open the conical envelop 17 and then penetrate the frangible disk 7 in the cap 3, thus opening the tell-tale hole to the atmosphere. Pressure ofwater and steam entering the from the spirit thereof ory cause the generatell-tale hole of the fractured bolt will now what We claim as new and vdesireto secure by Letters-Patent, is

1. A stay bolt having a pointed projectile Within said tell-tale hole, means Within said tell-tale' holeffor expelling said projectile upon the entrancev of moisture, and a destructible envelop, encircling the end of the pointed projectile.

' 2. A stay bolt having a tell-talehole, a pointed projectile therein, means in said tell-tale hole for expelling th'e-projectile upon the entrance of moisture,I and a de`- structible envelop inclosing the pointed end of the projectile and engaging the wall of the tell-tale hole to normally exclude moisf ture.

, 3. A stay bolt structure comprisinga-stay -Y i,lioxlt,having a tell-tale hole, a cap over the head ofthe bolt and having a .centraly opening, a destructibl disk normally closing said opening, a projectile Within said telltale hole and having av pointed end portion, means in said tell-tale hole for expelling said projectile upon the entrance of moisture, and a destructible cone inclosing the pointed end portion of the projectile and engaging the Wall of the tell-tale hole.k

' In testimony whereof',-We have signed thisspecification in the presenceiof two subscribing Witnesses.

JOHN 'ROGERS FLANNERY. BENJAMIN E. D. STAFFORD.

ETHAN I.' DODDS. Witnesses: Y F.-H.ALL1soN,

EDWIN S. RYGE. 

